Chromatography valve

ABSTRACT

A valve using a valve body having a plurality of valving elements, each valving element including three fluid ports located on a flat face of the valve body. Fluid passages are provided in the valve body to communicate with the fluid ports. A corresponding resilient member covers each valving element and is selectively urged toward the flat face to seal the fluid ports in the respective valving elements from each other. A pair of concentric fluid actuated plungers are slidably supported in a plunger body located on the other side of the resilient member from the valving element and having operative ends arranged to bear on the resilient member. The concentric plungers are selectively urged against the resilient member by either a fluid pressure supplied to a closed volume defined by the other ends of the concentric plungers, by the fluid pressure of a fluid being controlled by the valve or by a stationary spring means arranged to apply axial pressure to one of the plungers.

States Patent [191 CHROMATOGRAPHY VALVE [75] inventor: Jeffrey M. Lazar,Warminster, Pa. [73] Assignee: Honeywell lnc., Minneapolis, Minn. [22]Filed: Nov. 24, 1972 [21] Appl. No.: 309,495

Primary Examiner-Henry T. Klinksiek 'Attorney, Agent, or FirmArthur H.Swanson;

Lockwood D. Burton; Mitchell J. l-lalista m1 ansmze [4 1 Jan. 22, 1974[5 7 ABSTRACT A valve using a valve body having a plurality of valvingelements, each valving element including three fluid ports located on aflat face of the valve body. Fluid passages are provided in the valvebody to communicate with the fluid ports. A corresponding resilientmember covers each valving element and is selectively urged toward theflat face to seal the fluid ports in the respective valving elementsfrom each other. A pair of concentric fluid actuated plungers areslidably supported in a plunger body located on the other side of theresilient member from the valving element and having operative endsarranged to bear on the resilient member. The concentric plungers areselectively urged against the resilient member by either a fluidpressure supplied to a closed volume defined by the other ends of theconcentric plungers, by the fluid pressure of a fluid being controlledby the valve or by a stationary spring means arranged to apply axialpressure to one of the plungers.

7 Claims, 1 Drawing Figure CHROMATOGRAPHY VALVE CROSS REFERENCE TORELATED APPLICATION Subject matter shown but not claimed herein is shownand claimed in a co-pending application of Jeffrey M. Lazar, Ser. No.268,853, filed on July 3, 1972 and assigned to the same assignee as thepresent application.

BACKGROUND OF THE INVENTION Valves using flexible diaphragms as asealing member for fluid ports are well known in the art, e.g., suchvalves are shown in U.S. Pat. Nos. 3,140,615; 3,464,448 and 3,613,729.However, such valves have generally been found to be unsuitable forusing controllingextremely small fluid quantities, e.g., less than amicroliter. Current chromatographic analyzers use samples of a fluid tobe analyzed having a volume of less than 1 microliter in order toexpedite the processing of thesample andthe detection of the fluidconstituants. Thus the sampling valve for chromatographic analysis isused to selectively direct a sample of a fluid to be analyzed into afluid storage volume, and subsequently, inject the stored sample into afluid analyzing stream including a chromatographic absorption column forseparating constituents from the fluid sample. In order to allow such asystem to operate as a sensor for a chemical process, the sampling valvemust be capable of handling the aforesaid small volume of the samplefluid to be analyzed as well as incorporating a fluid-tight valvestructure to prevent the fluid sample from becoming contaminated.Additionally, the sampling valve must be capable of a relatively highspeed operation and contain a minimal dead space, i.e., extraneous fluidstorage volume, within the valve body. Finally, the sampling valveshould be operable over a wide range of fluid sample pressures in orderto be adaptable for sampling high and low pressure sample streams. Inorder to standardize the quantity of the fluid sample extracted from thefluid stream for analysis, the storage loop is preferably integrated aspart of the valve structure wherebythe quantity of the sample ismaintained for each analysis at a standardized value and externalconnections to the valve body are minimized.

Accordingly, it is an object of the present invention to provide animproved fluid valve for handling extremely small fluid quantities.

Another object of the present invention is to provide an improved fluidvalve having integral means for sequencing and storing test fluidssupplied to the valve.

SUMMARY OF THE INVENTION In accomplishing these and other objects, therehas been provided, in accordance with the present invention a valvehaving a valve block incorporating a valving element with each valvingelement including a plurality of fluid ports connected to a face of thevalve block and valve passages arranged to connect the valving elementswith a side surface of the valve block. An elastic diaphragm ispositioned above the face of the valve blockhaving the fluid portstherein and is selectively urged toward the face of the valve block by apair of fluid actuated plungers slidably supported in a valve platelocated on the other side of the diaphragm from the fluid ports. Acontact induced by either of the plungers between the diaphragm and theface of the valve block surrounding the fluid ports is effective to sealthe fluid ports in either of two port combinations to allow a fluidpassage between two of the valve ports in each combination. A recess isprovided in the valve body on the other side of the diaphragm from thefluid ports to allow the diaphragm to be displaced therein by fluidpressure from the fluid ports when a plunger is allowed to release thediaphragm. The valve plate is arranged to incorporate a fluid passagefor connecting a space defined by flanges on the plungers with anoutside surface of the valve plate. A spring means is arranged to applypressure to one of the plungers to normally bias this plunger into afirst fluid port sealing position. Second and third resilient diaphragmsare provided in contact with the center plunger to seal the spacedefined by the flanges of the plungers to isolate the actuating fluidpressure applied therein.

BRIEF DESCRIPTION OF THE DRAWING A better understanding of the presentinvention may behad when the following detailed description is read inconnection with the-accompanying single FIG. drawing which is a crosssection of a valve embodying the present invention.

DETAILED DESCRIPTION Referring to the single FIG. drawing in moredetail, there is shown a valve structure embodying the present inventionand incorporating a valve block 2. The following description uses suchterms as upper, lower, front and back and is intended only to refer tothe embodiment of the valve structure as is shown in the accompanyingillustrative drawing, while an actual valve, may, of course, be orientedin any desired manner whereby the aforesaid descriptive word would notbe directly applicable. Further, the term fluid as used herein refers toeither a liquid or gaseous fluid since the valve for the presentinvention is useable with either fluid medium. The valve block 2 has afirst side face 4 and a second side face 6. Further, the valve block 2has a lower, or first, end face 8 an upper, or second, end face 10 usedin first and second valving elements, respectively. A fluid storagebore, or volume, 12 is provided in the valve block 2 between the firstand second end faces 8 and 10. Thevolume of the bore 12 is arranged tobe consistent with the required volume of a sample fluid to be obtainedfor the chromatographic analysis. The location of the bore 12 betweenthe side faces 4 and 6 is determined by the location of other elementsof the valve, as described hereinafter.

A first fluid passage 14 is provided in the valve block 2 to connect thefirst side face 4 with the second end face 10. The end of the fluidpassage 14 exiting in the side face 4 may be provided with a threadedportion suitable for excepting a threaded connector for providing afluid tight connection to the fluid passage 14. A second fluid passage16 is provided in the valve block to connect the second side face 6 withthe second end face 10 and is, also, provided with a threaded portion atthe side face 6 to provide a means for obtaining a fluid-tightconnection to the fluid passage 16. The exit ports for the fluidpassages 14 and 16 are arranged to be on opposite sides of the bore 12and form part of a first valving element. A third fluid passage 18 isprovided in the valve block 2 to connect the first end face 8 with thefirst side face 4 and a fourth fluid passage 20 is provided in a valveblock 2 to connect the second side face 6 with the first end face 8. Thefluid passage 18 and 20 are also provided with threaded portions forobtaining fluid-tight connections thereto similar to those discussedabove with respect to fluid passages 14 and 16. The exit ports for thefluid passages 18 and 20 are, also arranged to be on opposite sides ofthe bore 12 and form part of a second valving element.

A first resilient member 22 is arranged to cover the second end faceand, consequently, the exit ports for the fluid passages 14 and 16 andone end of the bore 12. A second resilient member 24 is, similarly,arranged to cover the first end face 8 and the exit ports of the fluidpassages 18 and 20 and the other end of the bore 12. A valve plate 26 islocated on the other side of the first resilient member 22 from thevalve block 2. The valve plate 26 is arranged to slidably support twoconcentric plungers 28 and 30. The first plunger 28 is provided with anintegral peripheral annular ridge 32 at one end thereof and a flange 34at the other end. Similarly, the second plunger is provided with anintegral peripheral annular ridge 36.at one end thereof and a flange 38at the other end. The ridges 32 and 36 are arranged to be in contactwith the first resilient member 22. Further, the ridge 32 on the firstplunger 28 is arranged by virtue of the plunger 28 being supported inthe valve plate 26, to encompass within the area defined by the ridge 32the ports of the first fluid passage 14 and one end of the bore 12.Concurrently, the ridge 36 of the second plunger 30 is arranged toencompass an area only over the port end of the first fluid passage 14.

A first recess 39 is provided in the valve plate 26 adjacent to thefirst resilient member 22 and the encompassing an area on the resilientmember 22 which includes the ports of the first and second fluidconduits 14 and 16 and the bore 12. A second recess 40 is provided inthe other side of the valve plate 26 to admit the flange end 34 of thefirst plunger 28. A third resilient member 42 is arranged to cover theside of the valve plate 26 above the first resilient member 22. Further,the third resilient member 42 is provided with a center hole having adiameter smaller than the diameter of the second plunger 30. The plunger30 is provided with a circumerential recess 43 to accomodate the hole inthe third resilient member 42 whereby a fluid-tight connection betweenthe plunger 30 and the third resilient member 42 is obtained by thestretching of the resilient member 42 in the recess 43. An intermediateplate 44 is located on the other side of the third resilient member 42from the valve plate 26 and is provided with a center opening 45 ofsufficient diameter to admit the flange 38 of the second plunger 30while having a diameter smaller than the recess 40 in the valve plate 26whereby the intermediate member 44 overlies the recess 40 to act as astop for the flange 34 of the first plunger 28. A fluid passage 46 isprovided in the intermediate plate 44 between a side face thereof andthe central opening 45 therein. The end of the fluid passage 46 at theside face of the intermediate plate 44 may be provided with a threadedportion to effect a fluid-tight connection to the fluid passage 46. Afourth resilient member 47 is positioned above the intermediate plate 44and the flanged end 38 of the first plunger 30. A hollow rigid cover 48is located on the other side of the fourth resilient member 47 from theintermediate plate 44 and is used to clamp the fourth resilient member47 to the intermediate plate 44. A clamp plate 49 is located within thecover 48 in contact with the fourth resilient member 47 and is attachedto the flange 38 of the plunger 30 by any suitable means. A spring 50 islocated within the cover 48 between the inner surface of the cover 48and the clamp plate 49 to apply pressure against the second plunger 30.

A similar structure to that described above is positioned on the otherside of the first resilient member 8. Specifically, a second valve block52 is located on the other side of the first resilient member 8 from thevalve block 2. This second valve plate 2 is arranged to slidably supporta pair of concentric plungers 54 and 56. The first plunger 54 has anintegral peripheral annular ridge 58 at the end adjacent to the secondresilient member 8 and a flange 60 at the other end thereof. Similarly,the second plunger 56 has an integral peripheral annular ridge 62 at theend adjacent to the first resilient member 8 and a flange 64 at theother end thereof. The valve block 52 is provided with a recess 65 inthe end adjacent to the second resilient member 24 similar to the recess39 described above. Thus, the recess 65 is arranged to encompass an areaincluding the ports in the end face 8 of the valve block 2 correspondingto the third and fourth fluid passages 18 and 20 and the bore 12. Thevalve block 52 is also provided with a second recess 66 in the other endof the valve block 2 similar to the recess 40 described above withrespect to the first valve block 26. The recess 66 is arranged to have adiameter suitable for allowing movement of the flange 60 of the firstplunger 54 therein. A fifth resilient member 67 is positioned adjacentto the other end of the valve block 52 from the second resilient member24. A center opening in the fifth resilient member 67 is arranged tomate with a peripheral recess 68 located in the second plunger 56 toform a fluid-tight seal therewith. I

A second intermediate plate 69 is located on the other side of the fifthresilient member 67 from the valve block 52 and is provided with acenter hole 70 having a diameter sufficient to accomodate the flange 64of the second plunger 56. A fluid passage 71 is provided in theintermediate plate 69 between the slide face of the intermediate platesand the center hole 70. The fluid passage 70 may be provided with athreaded portion adjacent to the side face of the intermediate plate 69to provide means for effecting a fluid-tight connection to the fluidpassage 71. A sixth resilient member 72 is located in contact with theintermediate plate 69 on the other end from the fifth resilient member67. A hollow cover shell 73 similar to the shell 48 described above islocated on the other side of the sixth resilient member 72 to clamp thesixth resilient member 72 against the intermediate plate 69. A clampplate 74 is located on the other side of the flange 64 of the secondplunger 56 and is attached thereto by any suitable means whereby toclamp the sixth resilient member 72 between the flange 64 and the clampplate 74. A spring 76 is located between the clamp plate 74 and aninside surface of the cover 73 whereby to apply pressure to the secondplunger 56. The aforesaid layered construction of the valve may berigidly maintained by any suitable means such as bolts 78 passingthrough the layers and nuts 80 attached to the threaded end of the bolts78 whereby to clamp the aforesaid layered structure between the heads ofthe bolts and the nuts 80.

MODE OF OPERATION In operation, the valve shown in the single FIGUREdrawing is effective to provide a series of valve operations by theselective application of fluid pressures to the fluid passages 46 and71'. The effect of applying a fluid pressure to either of the fluidpassage 46 and 71 is illustrated in the upper half of the valve shown inthe single FIGURE drawing. Thus, the central plunger 30 is raisedagainst the pressure of the spring 50 with a consequent stretching ofthe third membrane 42 and the fourth membrane 47 while the outerconcentric plunger 28 is pushed against the first resilient member 22 toseal the resilient member 22 against the valve block 2 by the peripheralridge 32. On the other hand,

the position of the valve inner structure when the control fluidpressure is removed from the control fluid passages 46 and 71 isillustrated in the bottom of the valve structure shown in the singleFIGURE drawing. Thus, in the bottom half of the illustrated valvestructure, the control fluid pressure is not applied to the controlfluid passage 71. This lack of fluid pressure .within thecentral space70 of the intermediate plate 69 allows the spring 76 to push the plunger56 against the second resilient member 24. The annular ridge 62 of theplunger 56 is, accordingly, effective to seal the port of the fluidpassage 18 in the end face 8 of the valve block 2. Concurrently, thepressure of a fluid in the fluid sample storage bore 12 is effective tolift the portion of the second resilient member 24 above the port end ofthe bore 12 in the end face 8 and establish a fluid path between thebore 12 and the fluid passage having a port adjacent to the bore 12 inthe end face 8.

In order to operate the illustrated valve as a sampling valve, a controlfluid pressure is initially applied to the control fluid passages 46 and71 to produce a position of the plungers 28, 30, 54 and 56 in bothhalves of the valve to assume the state shown in the upper half of thevalve illustrated in the drawing. In this position, the fluid passage 14is connected by a fluid channel to the storage bore 12 which, in turn,is connected by a fluid passage under the second resilient member 24 tothe fluid passage 18. The fluid passages 16 and 20 are sealed by theresilient member 22 and 24, respectively, in response to a sealingpressure from the outer plungers 38 and 54, respectively. The source ofthe sample to be analyzed is connected to the fluid passage 14 while thefluid passage 18 is used as a vent. Accordingly, the fluid sample isflowing through the storage bore 12 during this operational state of thevalve. Subsequently, a sample of the fluid to be analyzed is obtained byremoving the-fluid pressure from both of the control fluid passages 46and 71 to allow the plungers 38, 30, 54 and 56 to assume the positionshown in the lower half of the valve structure shown in the drawing. Inthis operational state of the valve, the inlet sample passage 14 and thevent passage 18 are sealed and isolated by the resilient member 22 and24, respectively, while the fluid passages 16 and 20 are connected byfluid passages under the member 22 and 24, respectively, to respectiveends of the bore 12. The fluid passage 16 is connected to a source of acarrier gas while the fluid passage 20 is connected to a chromatographiccolumn. Thus, a carrier gas from the fluid passage 16 is now effectiveto sweep the fluid sample stored in the storage bore 12 into the fluidpassage 20 to be con veyed to the chromatographic column for analysis.The

size of the sample is, of course, determined by the volume of the fluidstorage bore 12. Subsequent operation of the valve is a recycling of theaforesaid sequence of operation to store a new sample in the storagebore 12 and, subsequently, to have this sample transferred to thechromatographic column by the carrier fluid supplied to the fluidpassage 16.

Accordingly, it may be seen that there has been provided, in accordancewith the present invention, an improved valve for handling extremelysmall fluid quantities and having integral means for sequencing andstoring a test fluid supplied to the valve.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A valve comprising a valve body having a plurality of fluid passagestherein extending between fluid ports in a face and a side of said valvebody,

a first resilient member covering said face of said valve body andencompassing the locations of said ports,

a pair of plungers positioned on the other side of said resilient memberfrom said valve body,

a valve block arranged to slidably support said pair of plungers,

a first one of said plungers having an operative end adjacent to saidresilient member and encompassing an area including a port of one ofsaid fluid passages in said face and a second one of said plungershaving an operative end adjacent to said resilient member andencompassing an area including another one of said ports of said fluidpassages in said face,

second resilient means forming a closed volume between the other end ofsaid first plunger and the other end of said second plunger,

means for introducing a control fluid into said closed volume, and

means for exerting a pressure against said first plunger to urge saidfirst plunger against said first resilient member.

2. A valve as set forth in claim 1 wherein said means for forming saidclosed volume includes a second and a third resilient member havingfluid-tight seals with said plungers. v

3. A valve as set forth in claim 1 wherein said first and secondplungers are concentric plungers and said area encompassed by saidoperative end of said second plunger includes said port encompassed bysaid area of said operative end of said first plunger.

4. A valve as set forth in claim 3 wherein said means for forming saidclosed volume includes a second and a third resilient member havingfluid-tight seals-with an inner one of said concentric plungers.

S. A valve as set forth in claim 4 wherein said means for exerting apressure includes a cover over said other end of first one of saidconcentric plungers and a spring means positioned between said cover andsaid other end of said first one of said concentric plungers.

6. A valve as set forth in claim 4 and including a fluid passage havinga port lying outside of the area encompassed by said annular ridge ofsaid second one of said concentric plungers.

7. A valve as set forth in claim 1 wherein said operative end of saidfirst plunger includes an annular ridge encompassing an area includingtwo of said ports of said fluid passages and including said port of saidone of said fluid passages.

1. A valve comprising a valve body having a plurality of fluid passagestherein extending between fluid ports in a face and a side of said valvebody, a first resilient member covering said face of said valve body andencompassing the locations of said ports, a pair of plungers positionedon the other side of said resilient member from said valve body, a valveblock arranged to slidably support said pair of plungers, a first one ofsaid plungers having an operative end adjacent to said resilient memberand encompassing an area including a port of one of said fluid passagesin said face and a second one of said plungers having an operative endadjacent to said resilient member and encompassing an area includinganother one of said ports of said fluid passages in said face, secondresilient means forming a closed volume between the other end of saidfirst plunger and the other end of said second plunger, means forintroducing a control fluid into said closed volume, and means forexerting a pressure against said first plunger to urge said firstplunger against said first resilient member.
 2. A valve as set forth inclaim 1 wherein said means for forming said closed volume includes asecond and a third resilient member having fluid-tight seals with saidplungers.
 3. A valve as set forth in claim 1 wherein said first andsecond plungers are concentric plungers and said area encompassed bysaid operative end of said second plunger includes said port encompassedby said area of said operative end of said first plunger.
 4. A valve asset forth in claim 3 wherein said means for forming said closed volumeincludes a second and a third resilient member having fluid-tight sealswith an inner one of said concentric plungers.
 5. A valve as set forthin claim 4 wherein said means for exerting a pressure includes a coverover said other end of first one of said concentric plungers and aspring means positioned between said cover and said other end of saidfirst one of said concentric plungers.
 6. A valve as set forth in claim4 and including a fluid passage having a port lying outside of the areaencompassed by said annular ridge of said second one of said concentricplungers.
 7. A valve as set forth in claim 1 wherein said operative endof said first plunger includes an annular ridge encompassing an areaincluding two of said ports of said fluid passages and including saidport of said one of said fluid passages.